L’objectif de ces travaux est le développement en technologie intégrée standard d’une topologiede ligne de propagation optimisée en termes de pertes, d’encombrement et de facteur de qualitéaux fréquences millimétriques. Cette topologie nommée S-CPW (Shielded CoPlanarWaveguide) utilise le phénomène d’ondes lentes afin de miniaturiser longitudinalement la ligned’un facteur compris entre 1,3 et 3,2 par rapport à des topologies classiques. Disposantégalement de faibles pertes, les lignes développées présentent un facteur de qualité élevé parfoissupérieur à 40, à 60 GHz. A partir de l’étude du champ électromagnétique dans la structure, unmodèle électrique a été développé. C’est le premier modèle dans la littérature prenant en compteles pertes dans ce type de guide d’onde. Plusieurs dispositifs passifs intégrés réalisés avec deslignes S-CPW dans différentes technologies CMOS ont été caractérisés jusqu’à 110GHz. Lacompacité et les faibles pertes d’insertion obtenues pour la mesure de filtres à stubs et dediviseurs de puissance permettent de réussir l’intégration de circuits passifs compacts entechnologie microélectronique CMOS standard aux fréquences millimétriques. / This work focuses on high-performance S-CPW (Shielded CoPlanar Waveguide) transmissionlines in classical CMOS integrated technologies for the millimeter-wave frequency band.Thanks to an important slow-wave phenomenon, the physical length of S-CPW decreases by afactor from 1.3 to 3.2 compared with classical transmission lines. Presenting also lowattenuation loss, the developed transmission lines show very high quality factor (higher than 40at 60 GHz). The precise study of the electromagnetism field leads to an electrical model forS-CPWs. This is the first model that takes the losses in this topology into account. Then, somebasic passive circuits designed with S-CPWs and characterized up to 110 GHz are presented invarious CMOS technologies. The low insertion losses and relative low surfaces of a powerdivider and a passband filter show the great interest of S-CPW to integrate compact passivecircuits in classical CMOS technologies at millimeter-wave frequencies.

Les télécommunications sont devenus indispensables dans notre monde actuel. De plus, le volume des données échangées ne cesse de croître. En effet, nous pouvons transmettre nos photos, nos vidéos au monde entier. Nonobstant, nous ne voulons pas attendre pour les avoir, ce qui exige un débit de données très important et par conséquent des signaux avec des bandes passantes plus larges. Les satellites de télécommunications doivent donc s’adapter, c'est pourquoi nous proposons dans ces travaux la recherche de filtre à large bande avec une recherche de compacité et de faibles pertes. Nous nous sommes intéressés à l'utilisation de matériaux céramiques qui permettent d'obtenir de bonnes performances vis à vis de nos besoins. Notre travail est aussi rendu possible par le développement de procédés de fabrication additifs, comme par exemple la stéréolithographie, qui va nous permettre de nous affranchir fortement de règles de dessin contraignantes que nous pourrions avoir en utilisant des procédés classiques. Nous avons développé des filtres avec de larges bandes passantes autour de 4GHz. Une première étude nous a permis de rechercher des concepts qui permettent d'obtenir de forts couplages, conditions sine qua non pour réaliser ces filtres. Plusieurs concepts sont présentés ainsi que leur fabrication et leur mesures. Nous avons ainsi démontré expérimentalement que les concepts proposés, à base de pièces monoblocs céramiques, sont capables de produire des filtres à bandes passantes supérieures à 60 % (voire même 110 % pour une version améliorée). / Every day, the data exchanges increase thanks to the new technologies. We can keep our files, our pictures, our videos online to have an access anywhere on the planet (for now). In this way, the data output of the telecommunication systems has to be increased in order to satisfy the more and more demanding users. One way to allow this is to increase the bandwidths of the different signals, making possible to transmit more data at the same time. In this work, we will develop wide bandpass filters dedicated to space telecommunications. For that purpose, we need them to be compact, with low insertion loss and a limited number of parts to assemble. Consequently, we are interested to use resonators made with ceramic materials that permits to reach such properties. Moreover, these materials are compatible with stereolithography, an additive manufacturing process. Such technology is here very useful for our purpose since its design freedom allows the creation of almost all kind of geometries. To realize such wide bandpass filters, we need strong couplings between the different resonators and also for the accesses, so we will present our studies focused on reaching these specific objectives. Then, we will present different designs of wide bandpass filter around 4GHz. After different generation of ceramic based components, we are be able to experimentally create a 60% bandwidth (even 100% for our last version) very compact bandpass filter filling the objectives of this PhD thesis.

Among the renewable energies, wind energy presents the highest growth in installed capacity and penetration in modern power systems. This is why reliability of wind turbines becomes an important topic in research and industry. To this end, condition monitoring (or health monitoring) systems are needed for wind turbines. The core of any condition monitoring system (CMS) are fault diagnosis algorithms whose task is to provide early warnings upon the occurrence of incipient (small magnitude) faults. Thanks to the use of CMS we can avoid premature breakdowns and reduce significatively maintenance costs.<p><p>The present thesis deals with fault diagnosis in sensors of a doubly-fed induction generator (DFIG) for wind turbine (WT) applications. In particular we are interested in performing fault detection and isolation (FDI) of incipient faults affecting the measurements of the three-phase signals (currents and voltages) in a controlled DFIG. Although different authors have dealt with FDI for sensors in induction machines and in DFIGs, most of them rely on the machine model with<p>constant parameters. However, the parameter uncertainties due to changes in the operating conditions will produce degradation in the performance of such FDI systems.<p><p>In this work we propose a systematic methodology for the design of sensor FDI systems with the following characteristics: i) capable of detecting and isolating incipient additive (bias, drifts) and multiplicative (changes in the sensor<p>gain) faults, ii) robust against changes in the references/disturbances affecting the controlled DFIG as well as modelling/parametric uncertainties, iii) residual generation system based on a multi-observer strategy to enhance the isolation process, iv) decision system based on statistical-change detection algorithms to treat the entire residual and perform fault detection and isolation at once.<p><p>Three novel sensor FDI approaches are proposed. The first is a signal-based approach, that uses the model of the balanced three-phase signals (currents or voltages) for residual generation purposes. The second is a model-based approach<p>that accounts for variation in the parameters. Finally, a third approach that combines the benefits of both the signal- and the model-based approaches is proposed. The designed sensor FDI systems have been validated using measured voltages, as well as simulated data from a controlled DFIG and a speed-controlled induction<p>motor. <p><p>In addition, in this work we propose a discrete-time multiple input multiple output (MIMO) regulator for each power converter, namely for the rotor side converter (RSC) and for the grid side converter (GSC). In particular, for RSC<p>control, we propose a modified feedback linearization technique to obtain a linear time invariant (LTI) model dynamics for the compensated DFIG. The novelty of this approach is that the compensation does not depend on highly uncertain parameters such as the rotor resistance. For GSC control, a LTI model dynamics<p>is derived using the ideas behind feedback linearization. The obtained LTI model dynamics are used to design Linear Quadratic Gaussian (LQG) regulators. A single design is needed for all the possible operating conditions. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

This thesis is dedicated to the study of the interaction between a gas jet and a liquid film on a moving surface. This flow configuration corresponds to the gas-jet wiping technique, which is widely used in the coating industry to reduce and control the thickness of a liquid film dragged by a moving substrate. For that purpose, a turbulent slot jet impinges on the liquid surface, involving a runback flow and consequently a lower coating thickness downstream wiping. The different process parameters (nozzle pressure, nozzle to substrate standoff distance, slot width, substrate speed) allow controlling the final film thickness. This metering technique is very common in coating processes, such as the application of gelatin layers on photographic films.<p><p>The first part of this thesis deals with the prediction of the mean jet wiping flow, i.e. the film thickness distribution in the wiping region. A lubrication model is developed for that purpose, which is simplified to a zero-dimensional model giving directly the final thickness<p><p>In the second part, the prediction of splashing occurrence in jet wiping is addressed. The splashing phenomenon in jet wiping is featured by the ejection of droplets from the runback flow, and it constitutes a physical limit to the process. An experimental investigation is conducted on a water model facility, and based on a phenomenological description, a dimensionless correlation in terms of film Reynolds number and jet Weber number is derived for splashing occurrence. The latter is perfectly well validated with observations on industrial lines.<p><p>The last part of this thesis is dedicated to the study of the unsteady phenomena occurring on the free surface of the liquid film downstream wiping. This phenomenon has never been understood nor characterized up to now. In the present research, undulation is investigated both theoretically and experimentally. Two model test facilities with dedicated measurement techniques have been designed and constructed. They allow performing parametric studies of the undulation characteristics (amplitude, wavelength, wave velocity), and analyzing the jet/film interaction.<p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

This thesis presents the derivation of the theory leading to the determination of the governing equations of chemically reacting flows under local thermodynamic equilibrium, which rigorously takes into account effects of elemental (de)mixing. As a result, new transport coefficients appear in the equations allowing a quantitative predictions and helping to gain deeper insight into the physics of chemically reacting flows at and near local equilibrium. These transport coefficients have been computed for both air and carbon dioxide mixtures allowing the application of this theory to both Earth and Mars entry problems in the framework of the methodology for the determination of the catalytic activity of Thermal Protections Systems (TPS) materials.<p>Firstly, we analyze the influence of elemental fraction variations on the computation of thermochemical equilibrium flows for both air and carbon dioxide mixtures. To this end, the equilibrium computations are compared with several chemical regimes to better analyze the influence of chemistry on wall heat flux and to observe the elemental fractions behavior along a stagnation line. The results of several computations are presented to highlight the effects of elemental demixing on the stagnation point heat flux and chemical equilibrium composition for air and carbon dioxide mixtures. Moreover, in the chemical nonequilibrium computations, the characteristic time of chemistry is artificially decreased and in the limit the chemical equilibrium regime, with variable elemental fractions, is achieved. Then, we apply the closed form of the equations governing the behavior of local thermodynamic equilibrium flows, accounting for the variation in local elemental concentrations in a rigorous manner, to simulate heat and mass transfer in CO2/N2 mixtures. This allows for the analysis of the boundary layer near the stagnation point of a hypersonic vehicle entering the true Martian atmosphere. The results obtained using this formulation are compared with those obtained using a previous form of the equations where the diffusive fluxes of elements are computed as a linear combination of the species diffusive fluxes. This not only validates the new formulation but also highlights its advantages with respect to the previous one :by using and analyzing the full set of equilibrium transport coefficients we arrive at a deep understanding of the mass and heat transfer for a CO2/N2 mixture.<p>Secondly, we present and analyze detailed numerical simulations of high-pressure inductively coupled air plasma flows both in the torch and in the test chamber using two different mathematical formulations: an extended chemical non-equilibrium formalism including finite rate chemistry and a form of the equations valid in the limit of local thermodynamic equilibrium and accounting for the demixing of chemical elements. Simulations at various operating pressures indicate that significant demixing of oxygen and nitrogen occurs, regardless of the degree of nonequilibrium in the plasma. As the operating pressure is increased, chemistry becomes increasingly fast and the nonequilibrium results correctly approach the results obtained assuming local thermodynamic equilibrium, supporting the validity of the proposed local equilibrium formulation. A similar analysis is conducted for CO2 plasma flows, showing the importance of elemental diffusion on the plasma behavior in the VKI plasmatron torch.<p>Thirdly, the extension of numerical tools developed at the von Karman Institute, required within the methodology for the determination of catalycity properties for thermal protection system materials, has been completed for CO2 flows. Non equilibrium stagnation line computations have been performed for several outer edge conditions in order to analyze the influence of the chemical models for bulk reactions. Moreover, wall surface reactions have been examined, and the importance of several recombination processes has been discussed. This analysis has revealed the limits of the model currently used, leading to the proposal of an alternative approach for the description of the flow-surface interaction. Finally the effects of outer edge elemental fractions on the heat flux map is analyzed, showing the need to add them to the list of parameters of the methodology currently used to determine catalycity properties of thermal protection materials. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

No description available.

In July of 1853, Chief Wakara's band of Utes clashed in a series of violent confrontations with the Mormon settlers. This conflict is known as the Walker War. Many complex factors contributed to this war. After some earlier violence between Mormons and different bands of Utes between 1847 and 1851, the Mormons continued their quick expansion settling on Ute lands. From 1851 to 1853 Mormon and Ute relations continued to decline as Mormons expanded their settlements occupying Ute hunting grounds. In addition to these land encroachments, new laws were enacted regulating trade between the Spanish and Utes by Brigham Young. The most notable regulation on trade prohibited the Spanish and Ute slave trade. All these trade regulations hurt the Ute economy, particularly the most powerful equestrian Ute band, the Cheverets led by Chief Wakara. In the spring of 1853 Governor Brigham Young ordered out the state militia to arrest Mexican traders and to capture Wakara for engaging in the slave trade. Wakara had previously established a friendly relationship with Young and had invited the Mormons to settle his lands in Sanpete. Wakara had become committed to peaceful relations and cooperation with Young and the Mormon people. Wakara remained true to his desire for friendly relations even after seeing his economic status undermined by Mormon settlers. Young as well was committed to staying on peaceful terms with the Utes. Their followers, on the other hand, had difficulties overcoming the cultural divide. After the murder of a member of Wakara's band in July of 1853 by settler James Ivie, Wakara's band waged a series of raids against Mormon settlements. Wakara himself, however, was not involved in the war and continually tried to sue for peace. The war has been mislabeled with Wakara's name; he was not really involved in the violence. Yet it was indeed a war. The war had a great impact on the Mormon settlers. Settlers abandoned their homes and had to move into forts. For the Mormons involved, this conflict was neither small nor inconsequential; it was a major disruption involving a great portion of the Utah Territory.

This thesis examines issues of cultural identity and modernity, and the anthropology of spirituality and sacred sites by conducting ethnographic research on fairy beliefs in contemporary Ireland. Irish folk belief has traditionally identified a spirit world intertwined with our own which is inhabited by spirits, often collectively referred to as fairies. Belief in these spirits was once widespread. My research sought to determine the prevalence of these traditional beliefs among modern Irish people within my research area, as well as differences in belief across variables including age, gender, and religious preference. I conducted eight weeks of ethnographic fieldwork during June-August 2008 in and around Sligo Town in County Sligo, Ireland. I selected County Sligo as a research site because it is a sparsely populated, largely rural area, identified in an earlier major study of Irish folklore as a region where belief in the Irish spirit world persisted more strongly than in other parts of the country. My primary research methodology was to conduct structured and unstructured interviews, complemented by visual site surveys. In the preparation of this thesis I utilized data from 52 Sligo residents plus ten other visitors to the area from surrounding Irish counties. While my research suggests that few Sligo residents from the project area continue to believe in the literal existence of fairies, it also shows a much more common belief in a "power" associated with sites identified as "fairy forts," which are natural features of the landscape or the remains of ancient burials or dwellings apocryphally endowed by folk tradition with supernatural or mysterious energies. These beliefs led to a taboo against intruding on, altering, or destroying these "forts" that is still very much alive today. Additionally I was able to discuss at length the subject of the Irish death-herald spirit called the banshee (bean sidhe) with several study participants. Although it can be classified under the umbrella label of "fairy", my research indicates that the banshee is seen as a stand-apart element of Irish tradition by research area residents, and is believed in by those who do not otherwise profess a belief in "fairies" in general.

No description available.

En période magnétiquement perturbée il est nécessaire de considérer une fonction de distribution des vitesses ioniques non-Maxwellienne, si l'on veut pouvoir estimer correctement les paramètres ionosphériques de l'ionosphère aurorale, mesurés par diffusion incohérente. Nous avons comparé deux modèles de fonction de distribution non-Maxwellienne : l'approximation polynomiale généralisée qui est une solution analytique de l'équation de Boltzmann et une distribution numérique basée sur une méthode Monte Carlo. Ces deux approches conduisent, pour les deux espèces ioniques 0+ et NO+, à des résultats semblables lors de champs électriques inférieurs à 100 m V lm. La fonction analytique a été introduite dans l'analyse des spectres EISCAT afin d'étudier l'ionosphère sous des champs électriques pouvant atteindre 100 m V /m. Cette nouvelle analyse a, dans un premier temps, été testée sur plusieurs jeux de simulations avec notamment des études de sensibilité aux modèles utilisés. Dans une seconde étape, nous avons étudié des spectres présentant des caractéristiques non-Maxwelliennes et avons ainsi déterminé la composition de l'ionosphère sous forts champs électriques. Enfin avec une dernière série de données réelles nous avons estimé quantitativement l'erreur commise lors d'une interprétation "Maxwellienne" de spectres non-Maxwelliens dans le cas d'une ionosphère composée d'ions moléculaires.